    [Patent document 1] JP-2009-243397 A
For example, Patent document 1 recites a power train control method which enables convergence to a target output without varying an actual output. This power train control method simulates, based on a target acceleration, a predicted acceleration on a vehicle power train model that includes a vehicle model having an engine model and a transfer model relative to a drive. The simulated predicted acceleration is fed back to a control of the target acceleration. In particular, an operation quantity of an engine (also referred to as a virtual control parameter) is adjusted based on a difference between the predicted acceleration and the target acceleration and outputted to the engine model. The virtual control parameter includes a throttle opening, an ignition time, a valve phase angle, and an injection quantity. The engine model outputs a predicted value (target torque) of a torque outputted from the engine, based on the received operation quantity. The vehicle model receives the target torque and outputs a predicted value of the acceleration generated on the vehicle (predicted acceleration).
Thus, the power train control method of Patent document 1 does not execute a feedback control using an actual acceleration, but executes a feedback control using a predicted acceleration. This eliminates an influence of a disturbance factor and stabilizes a target acceleration and a target torque.
As explained in the above, the technology of Patent document 1 intends to adjust the virtual operation quantity of the engine so as to make the predicted acceleration converge to the target acceleration.
A behavior of the vehicle such as an acceleration may not be determined only depending on an operating state of the engine. For example, suppose a hybrid system equipped with an engine and an electric motor as a driving source. In this system, the behavior of the vehicle is determined by a comprehensive operation of several subsystems such as the engine and the motor. In such a case, if not taking into the consideration not only the operation of the engine but also the operations of other subsystems which have an influence on the behavior of the vehicle, the behavior of the vehicle cannot approach the target behavior.
To that end, the following may be considered. That is, a target value relative to a behavior of the vehicle is calculated. According to the target value, several subsystems are operated in cooperation, thereby achieving a target behavior. In this case, a target behavior may be estimated. This target behavior should be demonstrated in the vehicle when several subsystems are operated according to the target value. When the actual behavior of the vehicle shifts from the target behavior, the target value may be amended. Therefore, the behavior of the vehicle can approach the target behavior.
However, there is a case where an anomaly arises in a subsystem or a transitional behavior arises in a subsystem. In such a case, it may become difficult to bring the actual behavior close to the target behavior only by correcting the target value relative to the vehicle behavior.